Plain English Meaning

A curved part of an RNAV route that follows a precise arc of a set distance from a center point, ending at a specific waypoint. The aircraft flies the same exact curved path every time, instead of cutting the corner.

Full Definition

A type of RNAV path segment defined as a curved track of fixed radius between two waypoints, centered on a defined turn center, ending at a named fix. Unlike a standard fly-by turn, an RF leg specifies the exact ground track of the turn, allowing flight management systems to fly a precise, repeatable arc rather than approximating the curve.